On Mon, 29 Jul 2013 17:23:24 -0400, Spehro Pefhany
wrote:

On Fri, 26 Jul 2013 21:42:45 -0400, Tom Gardner Mars@Tacks wrote:

On 7/23/2013 1:51 PM, Spehro Pefhany wrote:
On Tue, 23 Jul 2013 17:56:28 +0100, Syd Rumpo
wrote:

On 23/07/2013 17:44, Jim Wilkins wrote:
"Spehro Pefhany" wrote in message
...
On Tue, 23 Jul 2013 08:48:49 -0400, "Jim Wilkins"
wrote:


I can get the pins relatively clean pretty easily. The goal is to
have
nice shiny gold plated pins again, like new, so they can be used as
contact surfaces.

Right now I'm thinking mechanical abrasion to get down to the bare
metal (which is relatively hard) then nickel plate, then gold plate.

http://www.electrochem.org/dl/ma/203/pdfs/2374.pdf

Solder dissolves gold plating quickly.
http://www.eng-tips.com/viewthread.cfm?qid=7370

jsw

Of course, there is that approach. Dip the pins first into a pot of
molten gold to dissolve the Pb/Sn, then in another pot of clean molten
gold to re-plate. You'd need a nitrogen atmosphere, I think, so you're
already 80% there, and the pots of gold can be supplied by leprechauns.

Sláinte

Cost aside, I think the molten gold might cause the ceramic to crack.



I'd be interested to know how you finally solve this.

Sure, Tom.. it may be one of those things where I make my best
recommendations on how to do a top quality job and it ends up being
done differently for other reasons. There's a lot of $$ at stake.
Caswell has a gold brush plating setup for a quite reasonable price,
but everything involves some risk.
Greetings Spehro,
I have been reading this thread and thinking about the problem. I
tried myself to remove some solder mechanically from some gold plated
pins. I used an abrasive impregnated nylon brush, the type that mounts
to a buffer motor, to remove the solder. It worked pretty well.
Getting between the pins was tough but the brush I have is pretty
coarse. The gold came off too. I have used the silver brush plating
kit from Caswell and it worked quite well. If the gold kit works as
well it will be easy to re-plate the pins.
Eric